Stokes, K, Williams, S, McKay, C, West, S, Roberts, S, Tannhauser Sant'Anna, R, Kemp, S P T, Hagel, B & Cross, M 2021, ' Padded headgear does not reduce the incidence of match concussions in professional men's rugby union : a case-control study of 417 cases ', International Journal of Sports Medicine, vol. 42, no. 10, pp. 930-935 . https://doi.org/10.1055/a-1345-9163